Biofeedback Posture Training for Adolescents with Mild Scoliosis.

Adolescent idiopathic scoliosis (AIS) is characterized by uneven shoulders, spinal curvature, and uneven hips, and asymmetry in paraspinal muscle activities is common in AIS. This pilot study was aimed at examining the use of a surface electromyography (sEMG) biofeedback posture training program in adolescents with mild scoliosis (Cobb's angle < 30°) to attenuate asymmetry in paraspinal muscle activities and control the curve progression. Seven female adolescents (age, 12-14 years) with mild scoliosis (Cobb's angle < 30°) were recruited. The participants received 30 tailor-made sessions of sEMG biofeedback posture training at a rate of one to two sessions per week for approximately 6 months. The activities of the paraspinal muscles (the trapezius, latissimus dorsi, thoracic erector spinae, and lumbar erector spinae) measured by sEMG during habitual sitting postures and spinal deformity evaluated by 3D ultrasound imaging were compared before and after training. The mean values of the root-mean-square sEMG ratio, an index of symmetry in paraspinal muscle activities of the muscle pairs between the concave and convex sides of the spinal curve, revealed significant asymmetry over the trapezius and lumbar erector spinae before the training (p <0.05). After the training, all seven adolescents achieved relatively more symmetrical paraspinal muscle activities over these two muscle pairs (p < 0.05). In two adolescents, the spinal curvature decreased by 5.7° and 5.6°, respectively, whereas the remaining adolescents showed a minimal curve progression with changes in the spinal curvature controlled under 5°. To conclude, sEMG biofeedback posture training can reduce asymmetry in paraspinal muscle activities and control curve progression in adolescents with mild scoliosis and can potentially be considered an alternative early intervention for muscle reeducation in this cohort.

Effects of Corrective Exercises on Posture, Pain, and Muscle Activation of Patients With Chronic Neck Pain Exposed to Anterior-Posterior Perturbation.

OBJECTIVES: This study aimed to evaluate the effects of corrective exercises on posture, pain, and muscle activation of patients with chronic neck pain exposed to anterior-posterior perturbation. METHODS: A total of 32 women (37.76 ± 3.83 years) with chronic, nonspecific neck pain were randomized into corrective exercise and control groups. The experimental group underwent a corrective exercise program for 8 weeks, 30 min/d, 3 days per week. The control group received active self-exercise instructions. Neck pain, forward head and protracted shoulder posture, and timing of superficial neck muscle activation were evaluated using the visual analog scale, photogrammetry, and electromyogram, respectively, before and then 48 hours after the 8-week program for both the experimental and control groups. All measurements at pretest and posttest were taken by a blinded assessor. RESULTS: Significant alterations were observed in cervical angle (P = .003, effect size = 0.329), shoulder angle (P = .008, effect size = 0.457), neck pain and disability (P = .009, effect size = 0.645), movement control (P = .038, effect size = 0.353), activation onset of the upper trapezius (P = .015, effect size = 0.746), the sternocleidomastoid (P = .018, effect size = 0.879) and cervical erector spinae (P = .031, effect size = 0.765), and the root mean square of the upper trapezius (P = .033, effect size = 0.742), the sternocleidomastoid (P = .041, effect size = 0.587), and the cervical erector spinae (P = .024, effect size = 0.832) in the intervention group from pre- to posttest (P < .05). CONCLUSION: Positive and significant alterations have been observed in the forward head and protracted shoulder posture, the timing of superficial neck muscle activation, neck pain, and disability in female patients with chronic neck pain exposed to anterior-posterior perturbation after performing an 8-week corrective exercise program.

Short-term effects of two deep dry needling techniques on pressure pain thresholds and electromyographic amplitude of the lumbosacral multifidus in patients with low back pain - a randomized clinical trial.

Objectives: The purpose of this study was to compare the effects of deep dry needling (DN) with and without needle manipulation on pressure pain thresholds (PPTs) and electromyographic (EMG) amplitude of the lumbosacral multifidus (LM) in adults with low back pain (LBP). Methods: Participants were randomized into two treatment groups: with needle manipulation (n = 21) and without needle manipulation (n = 21). All participants received a single session of the assigned DN intervention. PPTs and EMG amplitude of the LM muscle were collected three times: before DN, immediately after DN, and one week after DN. Results: The needle manipulation group had a significantly greater increase in PPT immediately after the intervention and at the one-week follow-up as compared to the no needle manipulation group. The increase of PPT in the needle manipulation group was significant immediately after the intervention, and the increase remained significant at the one-week follow-up. However, there was no significant difference in EMG amplitude of the LM muscle between groups across the three time points. Discussion: Deep DN with needle manipulation appeared to reduce mechanical pressure sensitivity more than DN without manipulation for patients with LBP. Although a single session of DN could reduce pressure pain sensitivity, it may not be sufficient to improve LM muscle function. Level of Evidence: 1b. Trial registration numbers: NCT03970486.

A study on the paraspinal muscle surface electromyography in acute nonspecific lower back pain.

Aim of this study was to determine if surface electromyography (sEMG) could provide objective data in monitoring the alteration of signal amplitude of myoelectric activity of the paraspinal muscles in the patients with acute nonspecific lower back pain (ANLBP), and to explore the correlation between sEMG data and symptom relief in the ANLBP patients before and after massage therapy.Forty-five ANLBP patients and 20 healthy subjects were enrolled into this study. Patients were given massage therapy for 1 week. The average electromyography (AEMG), visual analogue scale (VAS), and distance of finger to floor (DFTF) were measured before and after treatment.AEMG at flexion and maintained flexion positions were significantly higher in the ANLBP group compared to that in the control group. At extension position, in contrast, AEMG was significantly lower in the ANLBP patients than that of control group, and there was no significant difference between the 2 groups at upright position. After massage therapy for the ANLBP patients, AEMG was significantly reduced at flexion and maintained flexion positions, but significantly increased at extension position than that before treatment. VAS and DFTF were also significantly reduced after treatment. In addition, AEMG alteration at maintained flexion position was significantly correlated with improvement of VAS or DFTF.Myoelectric activity of the paraspinal muscles in the ANLBP patients was different from that of healthy subjects. Massage therapy not only relived patients' symptoms, but also normalized myoelectric activity of the paraspinal muscles in the ANLBP patients.

Effect of Massage on Clinical and Physiological Variables During Muscle Fatigue Task in Participants With Chronic Low Back Pain: A Crossover Study.

OBJECTIVE: The purpose of this study was to determine if a reduction of short-term physiological and clinical effects of muscle fatigue can be seen after a session of massage in nonspecific chronic low back pain (cLBP) individuals and to study the possible association between physiological and clinical changes induced by massage. METHODS: Thirty-six cLBP individuals participated in 2 experimental sessions. In one session, the Sorenson protocol was preceded by a 30-minute massage, but in the other session, only the Sorenson test was performed by participants. Lumbar paraspinal muscle activity was recorded using surface electromyography, and maximal voluntary contraction force was measured using a load cell. Participants rated their lumbar pain intensity before and after massage and after the Sorensen protocol. A 2-way repeated-measures analysis of variance was conducted to test the effect of massage on both variables for both conditions. Pearson correlation analyses were conducted to determine the linear association between physiological and clinical responses to massage. RESULTS: Results showed that pain perception was significantly reduced after massage (P = .004) but did not seem to influence pain score increases occurring after the Sorensen protocol. Individuals with a high score of low back pain-related disability showed lower back muscle endurance time (r = -.35). Massage yielded no significant effect on fatigue-related physiological variables. CONCLUSION: The perception of pain in cLBP individuals was reduced after massage. Although massage yielded some positives clinical effects, they were not explained by a reduction in physiological effect of muscle fatigue.

Effects of tactile feedback on lumbar multifidus muscle activity in asymptomatic healthy adults and patients with low back pain.

BACKGROUND: Reduced lumbar multifidus (LM) muscle contraction has been observed in patients with low back pain (LBP). Clinicians often use various strategies to ensure LM activation, including tactile feedback and verbal instruction. However, the effects of tactile feedback on muscle activation have not been studied previously. Therefore, the purpose of this study was to investigate whether or not tactile feedback would increase LM muscle activity in adults with and without LBP. METHODS: Twenty asymptomatic adults and 20 patients with existing LBP completed the study. Two electromyographic (EMG) electrodes were applied to both sides of the LM at the L5 segment. EMG activity was collected three times at rest with and without tactile feedback, then five times during contralateral arm lifts with and without tactile feedback. The tactile feedback was applied by direct and continuous hand contact to the bilateral LM over the lumbosacral area. Lastly, two 5-second trials of maximum voluntary isometric contraction (MVIC) during a bilateral arm lift were performed. EMG activity collected at rest and during contralateral arm lifts was normalized to that collected during MVIC. Normalized EMG values of the right side of the asymptomatic group and the painful side of the LBP group were used for data analysis. RESULTS: Statistical analysis showed significantly decreased LM EMG activity with tactile feedback both at rest and during contralateral arm lifts compared to LM EMG activity without tactile feedback. There was no difference in LM EMG between the asymptomatic and the LBP groups. CONCLUSIONS: The results of the study showed that adding tactile stimulation to verbal instruction appeared to provide an inhibitory effect on LM activity in both asymptomatic healthy adults and patients with LBP. Contrary to common belief, tactical feedback via direct hand contact may reduce LM muscle recruitment, and may lessen the desired treatment effect.

Comparison Between Transcutaneous Electrical Nerve Stimulation and Stabilization Exercises in Fatigue and Transversus Abdominis Activation in Patients With Lumbar Disk Herniation: A Randomized Study.

OBJECTIVE: The purpose of this study was to compare transcutaneous electrical nerve stimulation (TENS) and stabilization exercises in an attempt to prevent fatigue and improve muscle activation in patients with lumbar disk herniation associated with low back pain. METHODS: This study involved 29 patients (age range 25-58 years) randomized into 2 groups: the segmental stabilization group (n = 15), who received stabilization exercises on the transversus abdominis (TrA) and lumbar multifidus muscles; and the TENS group (n = 14), who received electrotherapy. Groups underwent 16 sessions, for 60 minutes, twice per week, and they were evaluated before and after intervention. Pain was measured using a visual analog scale, functional disability using the Oswestry Disability Index, muscle activation and fatigue with electromyography, and patients' ability to contract the TrA with a pressure biofeedback unit. Analyses within and between groups were performed. RESULTS: The stabilization group improved lumbar multifidus fatigue (median frequency [MF] initial [P = .002], MF final [P < .001], MF slope [P = .001], and resistance time [P < .001]), ability to contract the TrA (P < .001), pain (P < .001), and functional disability (P < .001). TENS only was effective for pain (P = .012). CONCLUSION: Although it relieved pain, TENS was not effective as a single treatment to prevent fatigue, increase TrA contraction, and reduce functional disability in herniated disk patients. Stabilization exercises alone improved all measured outcomes.

Effect of Thunder-Fire Moxibustion on Pain, Quality of Life, and Tension of Multifidus in Patients with Primary Osteoporosis: A Randomized Controlled Trial.

BACKGROUND Primary osteoporosis is a common disease among postmenopausal women and the elderly; low back pain is the most typical clinical manifestation an is the primary reason for a clinic visit, and directly affects patients' quality of life. Anti-osteoporosis medications have undesirable side effects, and many kinds of special traditional Chinese moxibustion methods have been widely used in the clinical treatment of osteoporosis low back pain. The purpose of this study was to observe whether thunder-fire moxibustion therapy, compared to calcium supplements alone, can ease osteoporosis low back pain, improve quality of life, and reduce tension of the multifidus. MATERIAL AND METHODS Sixty-three eligible patients were enrolled in the study (7 of these patients did not finish the study and are not included in analysis). Participants were randomly divided into 2 groups: a moxibustion group that received calcium carbonate D3 and thunder-fire moxibustion therapy, and a control group that received calcium carbonate D3 only. Level of pain experienced, assessed using the visual analogue scale (VAS), and quality of life (SF-36) were measured pre-treatment, at the end of 4 weeks of treatment, and at a 1-month post-treatment evaluation. Changes in values of Young's modulus of the multifidus were also collected before and after treatment. RESULTS After 4 weeks of treatment and at 1 month after treatment had ended, low back pain in both groups was reduced relative to pre-treatment levels. The moxibustion group was significantly improved at BP, GH, SF, and MH dimensions compared to pre-treatment levels. The control group improved in BP dimensions, but not to the same extent as the moxibustion group. Similarly, after treatment for 4 weeks with moxibustion, multifidus tension was significantly reduced. CONCLUSIONS Thunder-fire moxibustion is an effective method for treating low back pain due to primary osteoporosis.

Instrumented Measurement of Spinal Stiffness: A Systematic Literature Review of Reliability.

OBJECTIVE: The purpose of this review was to critically appraise the quality of studies evaluating the reliability of spinal stiffness assessment devices. METHODS: An electronic search of the MEDLINE, PubMed, CINAHL, PsycINFO, PEDro, and Embase databases up to September 2016 was performed. Information on participants, measurement protocols, reliability, and accuracy were extracted. Two reviewers independently applied the COnsensus-based Standards for the selection of health Measurement INstruments checklist to assess the methodological quality of the measurement properties reliability and measurement error, which were rated as excellent, good, fair, or poor. The overall score was determined using the worst score counts method. RESULTS: In total, 1,728 studies were identified and 9 studies were included in this review. All included studies showed high reliability, with intraclass correlation coefficient values ranging from 0.65 to 0.99. In the quality assessment, 2 studies were rated as fair and 7 studies as poor, mainly because of sample sizes. CONCLUSION: The studies demonstrated favorable high-reliability values but low methodological quality. In the future, high-quality studies with larger sample sizes are needed.

Analysis of Head Posture and Activation of the Cervical Neck Extensors During a Low-Load Task in Women With Chronic Migraine and Healthy Participants.

OBJECTIVE: The purpose of this study was to investigate the correlation between head and neck posture and superficial neck flexor and extensor activity during performance of the craniocervical flexion test (CCFT) in women with migraine and healthy controls. METHODS: Fifty-two women with episodic migraine, 16 with chronic migraine, and 23 healthy controls participated. Head and neck posture were determined by assessing the craniovertebral (CV) angle and cervical lordosis angle. Surface electromyography signals were recorded bilaterally from sternocleidomastoid, anterior scalene, splenius capitis, and upper trapezius muscles as participants performed the CCFT. Differences in electromyogram activity and posture among groups were compared with analyses of variance. Correlations between posture and electromyogram activity were analyzed with the Pearson correlation coefficient. RESULTS: Both migraine groups had a significant increase in splenius capitis muscle activity, when acting as an antagonist, at the last stage of CCFT (F = 4.687; P = .012) compared with controls. No differences among groups were observed for head and neck posture. No significant correlation was found in the episodic migraine group. Moderate correlations between the CV angle and upper trapezius activity at the majority stages of the CCFT (-0.61 < r < -0.65, all P < .05) were observed within the chronic migraine group: the more extended the head posture, the higher the activity of the upper trapezius muscle. The CV angle also was correlated with upper trapezius muscle activity at the first stage of the CCFT and with splenius capitis muscle activity at the last stages (-0.42 < r < -0.52; P < .05). CONCLUSION: An extended (forward) head posture was moderately correlated with an increased in electrical activity of superficial neck extensor muscles, particularly the upper trapezius, when acting as an antagonist, during the performance of the CCFT in women with chronic but not episodic migraine.

Immediate Changes in Resting and Contracted Thickness of Transversus Abdominis After Dry Needling of Lumbar Multifidus in Healthy Participants: A Randomized Controlled Crossover Trial.

OBJECTIVE: The purpose of this study was to investigate changes in resting and/or contraction thickness of the transversus abdominis (TrA) muscle after dry needling (DN) of the lumbar multifidus (LM) in asymptomatic participants. METHODS: A randomized controlled laboratory trial with crossover design was performed. Forty-seven healthy individuals who had not experienced low back pain in the previous 6 months were randomly assigned to receive DN to the LM or a sham-DN intervention. Participants received both interventions separated at least 7 days apart. They were instructed on how to perform a concentric contraction of TrA. Resting and contraction thicknesses of the TrA were obtained through real-time ultrasound measurements before and immediately after each intervention by an assessor blinded to the intervention received. Data from 4 individuals had to be excluded because of poor image quality. RESULTS: Two-way analysis of variance revealed a significant contraction with treatment interaction (F[1,42] = 11.489; P = .002). Simple main effects using paired-samples t tests and a Bonferroni post hoc analysis revealed differences in contracted states of the TrA for DN vs sham-DN (P = .009) and between contracted and resting states for the DN group (P = .001): after DN, TrA thickness at rest exhibited a mean decrease of 0.03 cm and a mean increase of 0.05 cm during contraction. CONCLUSION: This study suggests that application of DN to LM was accompanied by a decreased resting thickness and an increased contraction thickness of the TrA in asymptomatic participants.

Effect of MELT method on thoracolumbar connective tissue: The full study.

Altered connective tissue structure has been identified in adults with chronic low back pain (LBP). A self-care treatment for managing LBP is the MELT method. The MELT method is a hands-off, self-treatment that is said to alleviate chronic pain, release tension and restore mobility, utilizing specialized soft treatments balls, soft body roller and techniques mimicking manual therapy. The objective of this study was to determine whether thickness of thoracolumbar connective tissue and biomechanical and viscoelastic properties of myofascial tissue in the low back region change in subjects with chronic LBP as a result of MELT. This study was designed using a quasi experimental pre-post- design that analyzed data from subjects who performed MELT. Using ultrasound imaging and an algorithm developed in MATLAB, thickness of thoracolumbar connective tissue was analyzed in 22 subjects. A hand-held digital palpation device, called the MyotonPRO, was used to assess biomechanical properties such as stiffness, elasticity, tone and mechanical stress relaxation time of the thoracolumbar myofascial tissue. A forward bending test assessing flexibility and pain scale was added to see if MELT affected subjects with chronic LBP. A significant decrease in connective tissue thickness and pain was observed in participants. Significant increase in flexibility was also recorded.

The association between dry needling-induced twitch response and change in pain and muscle function in patients with low back pain: a quasi-experimental study.

OBJECTIVE: To investigate the relationship between dry needling-induced twitch response and change in pain, disability, nociceptive sensitivity, and lumbar multifidus muscle function, in patients with low back pain (LBP). DESIGN: Quasi-experimental study. SETTING: Department of Defense Academic Institution. PARTICIPANTS: Sixty-six patients with mechanical LBP (38 men, 28 women, age: 41.3 [9.2] years). INTERVENTIONS: Dry needling treatment to the lumbar multifidus muscles between L3 and L5 bilaterally. MAIN OUTCOME MEASURES: Examination procedures included numeric pain rating, the Modified Oswestry Disability Index, pressure algometry, and real-time ultrasound imaging assessment of lumbar multifidus muscle function before and after dry needling treatment. Pain pressure threshold (PPT) was used to measure nocioceptive sensitivity. The percent change in muscle thickness from rest to contraction was calculated to represent muscle function. Participants were dichotomized and compared based on whether or not they experienced at least one twitch response on the most painful side and spinal level during dry needling. RESULTS: Participants experiencing local twitch response during dry needling exhibited greater immediate improvement in lumbar multifidus muscle function than participants who did not experience a twitch (thickness change with twitch: 12.4 [6]%, thickness change without twitch: 5.7 [11]%, mean difference adjusted for baseline value, 95%CI: 4.4 [1 to 8]%). However, this difference was not present after 1-week, and there were no between-groups differences in disability, pain intensity, or nociceptive sensitivity. CONCLUSIONS: The twitch response during dry needling might be clinically relevant, but should not be considered necessary for successful treatment.

The Strengthening Effect of Electrical Stimulation on Lumbar Paraspinal Muscles in the Sitting Position: A Randomized Controlled Trial.

BACKGROUND: Sedentary lifestyle, a prevalent finding in modern society, can lead to weakness of the lumbar trunk musculature. Electrical stimulation (ES), in addition to lumbar strengthening exercises, has been shown to increase muscle strength. OBJECTIVE: To assess the strengthening effect of ES on the lumbar paraspinal muscles during prolonged sitting. DESIGN: Randomized, controlled, single-blind study. SETTING: Tertiary hospital. PARTICIPANTS: Thirty healthy subjects without low back pain. METHODS: Thirty participants were randomly assigned to the ES group (n = 15) or the control group (n = 15). ES was administered over the lumbar paraspinal muscles, while subjects maintained a seated posture, at a maximal tolerable intensity for 60 minutes per day, three times per week, for 4 consecutive weeks. An identical protocol was used in the control group with muscle stimulation provided at the minimal sensory threshold intensity. MAIN OUTCOME MEASUREMENTS: The isokinetic strength of the lumbar paraspinal muscles was evaluated at baseline, 4 weeks after the initiation of ES, and 8 weeks after the initiation of ES with an isokinetic dynamometer (Biodex Medical Dynamometer System-4) at 60°/s and 120°/s angular velocities. RESULTS: The extension and flexion peak torque at 60°/s showed no significant interaction between the time and intervention or between the interventions. However, after 4 weeks of ES in the sitting position, the isokinetic extensor trunk muscle strength measured at 120°/s angular velocity significantly increased in the ES group (P < .05) compared with that in the control group. This effect was not maintained when measured at 4 weeks after the cessation of ES. CONCLUSIONS: ES in a sitting position is a potentially effective and accessible rehabilitation treatment, which can lead to short-term improvement in the extensor trunk muscle strength of the lumbar paraspinal muscles. LEVEL OF EVIDENCE: I.

Effects of Weight-shifting Exercise Combined with Transcutaneous Electrical Nerve Stimulation on Muscle Activity and Trunk Control in Patients with Stroke.

This study investigated the effects of weight-shifting exercise (WSE) combined with transcutaneous electrical nerve stimulation (TENS), applied to the erector spinae and external oblique (EO) muscles, on muscle activity and trunk control in patients with hemiparetic stroke. Sixty patients with stroke were recruited to this study and randomly distributed into three treatment groups: (1) WSE + TENS, (2) WSE + placebo TENS, and (3) control. All participants underwent 30 sessions of training (30 minutes five times per week for 6 weeks) and received 1 hour of conventional physical therapy five times per week for 6 weeks. Muscle activity, maximum reaching distance and trunk impairment scale scores were assessed in all patients before and after the training. After training, the WSE + TENS group showed significant increase in the EO activity, maximum reaching distance and trunk impairment scale scores compared with the WSE + placebo TENS and control groups. These findings suggest that WSE with TENS applied to the erector spinae and EO muscles increased the trunk muscle activity and improved trunk control. Therefore, WSE with TENS could be a beneficial intervention in clinical settings for individuals with hemiparetic stroke. Copyright © 2016 John Wiley & Sons, Ltd.

Comparison of two angles of approach for trigger point dry needling of the lumbar multifidus in human donors (cadavers).

STUDY DESIGN: Descriptive comparison study. OBJECTIVE: To assess the accuracy of two needle angle approaches for dry needling of the lumbar multifidus. BACKGROUND: Low back pain is a leading cause of disability around the world; the lumbar multifidus plays a vital role in low back health. Manual therapy such as dry needling can improve pain mediation and motor control activation of the lumbar multifidus. Clinicians practicing dry needling at the lumbar multifidus typically use an inferomedial approach considered non-controversial. Clinicians practicing electromyography and nerve conduction studies commonly sample the lumbar multifidus in a directly posteroanterior approach that may provide another option for dry needling technique. METHODS: Four human donors were used for a total of eight needle placements-four with an inferomedial orientation and four with a posteroanterior orientation. Each needle was placed from 1 to 1.5 cm lateral to the spinous process of L4 to the depth of the lumbar lamina. Each lower lumbar spine was then dissected to determine the structures that the needle traversed and the needle's final resting place. RESULTS: All four inferomedial approach needles ended at the lamina of the vertebrae below. All four posterior-anterior approach needles ended in the lamina of the same level. CONCLUSIONS: All eight needles traversed the lumbar multifidus and ended in the lumbar lamina with little possibility of the needle entering the subarachnoid space. Thus both the inferomedial and the posteroanterior angles of approach are efficacious for clinicians to use in dry needling of the lumbar mulifidus.

Changes in lumbar multifidus muscle function and nociceptive sensitivity in low back pain patient responders versus non-responders after dry needling treatment.

BACKGROUND: Little is known about the physiologic mechanism of dry needling. While some evidence suggests that dry needling may decrease nocioceptive sensitivity and facilitate muscle function, no studies to date have examined these physiologic changes compared to clinical outcomes. OBJECTIVE: To examine changes in lumbar multifidus (LM) muscle function and nociceptive sensitivity after dry needling in patients with LBP and to determine if such changes differ in patients that exhibit improved disability (responders) and those that do not (non-responders). DESIGN: Quasi-experimental study. METHODS: Sixty-six volunteers with mechanical LBP (38 men, age = 41.3 ± 9.2 years) completed the study. Ultrasound measurements and pain algometry of the LM were taken at baseline and repeated immediately following dry needling treatment to the LM muscles and after one week. The percent change in muscle thickness from rest to contraction was calculated for each time point to represent muscle function. Pressure pain threshold (PPT) was used to measure nociceptive sensitivity. Participants were dichotomized as responders and non-responders based on whether or not they experienced clinical improvement using the modified Oswestry Disability Index after one week. 2 × 3 mixed-model ANOVA were conducted for group (responders vs. non-responders) by time. RESULTS: Patient responders exhibited larger improvements in LM muscle contraction and nociceptive sensitivity 1 week, but not immediately, after dry needling than non-responders. CONCLUSIONS: Our results suggest that there may be lasting and clinically relevant sensorimotor changes that occur in LBP patients that improve with dry needling treatment that partially explain the physiologic mechanism of action.

Loud preimpact tones reduce the cervical multifidus muscle response during rear-end collisions: a potential method for reducing whiplash injuries.

BACKGROUND CONTEXT: Neck muscle responses after unexpected rear-end collisions consist of a stereotypical combination of postural and startle responses. Prior work using surface electromyography (EMG) has shown that the superficial neck muscle responses can be attenuated when a loud tone (105 dB) is presented 250 milliseconds before impact, but the accompanying response of the deeper multifidus muscles remains unknown. Quantifying this response in multifidus is important because this muscle attaches directly to the cervical facet capsule and can potentially increase the strain in the capsule during an impact and contribute to whiplash injury. PURPOSE: To investigate if a loud preimpact tone decreases the cervical multifidus muscle response during rear-end perturbations. STUDY DESIGN: After approval by the University Clinical Ethics Review Board, human volunteers experienced a series of three whiplash-like perturbations. PATIENT SAMPLE: Twelve subjects with no history of neurologic disorders or whiplash injury were recruited to participate in this experiment. OUTCOME MEASURES: Bilateral indwelling EMG of multifidus at the C4 and C6 levels, surface EMG of sternocleidomastoid (SCM) and C4 paraspinals (PARAs), and kinematics of the head/neck were measured. METHODS: Subjects experienced three whiplash-like perturbations (peak acceleration of 19.5 m/s(2)) preceded by either no tone or a loud tone (105 dB) presented 250 milliseconds before sled acceleration onset. RESULTS: The loud tone decreased the muscle activity of C6 multifidus (42%) and C4 PARAs (30%), but did not affect the C4 multifidus or SCM activity. Peak head kinematic responses (extension angle: 6%, retraction: 9%, linear forward acceleration: 9%, and angular acceleration in extension: 13%) were also decreased by the loud preimpact tone. CONCLUSIONS: The attenuation of peak C6 multifidus activity and head kinematic responses suggests that a loud preimpact tone may reduce the strain in the cervical facet capsule, which may reduce the risk of whiplash injury during rear-end collisions.

Long-term lumbar multifidus muscle atrophy changes documented with magnetic resonance imaging: a case series.

A retrospective case series of three patients with chronic low back pain who received baseline MRI scans revealing multifidus muscle atrophy with fatty replacement is provided. Each patient received spinal manipulative therapy, and two were compliant with low back exercises targeting the multifidus. A follow-up scan performed >1 year later was compared to the baseline scan revealing a decrease in atrophy with fatty replacement in the two patients who performed multifidus-focused low back exercises (15% and 39% on the left and 7% and 32% on the right respectively), and an increase in the patient who underwent spinal manipulation alone (41% and 53%). Interestingly, the decrease in atrophy in the two patients that performed the exercises correlated to functional improvements. Though limited, these results highlight the utility of MRI in quantifying positive and negative long-term changes in multifidus atrophy, which may be an indicator of recovery in chronic low back pain patients.